Goto Section: 73.615 | 73.621 | Table of Contents
FCC 73.616
Revised as of October 2, 2015
Goto Year:2014 |
2016
§ 73.616 Post-transition DTV station interference protection.
(a) Applications seeking facilities that will operate prior to the end of
the DTV transition must also comply with § 73.623.
(b) A petition to add a new channel to the post-transition DTV Table of
Allotments contained in § 73.622(i) of this subpart will not be accepted
unless it meets: the DTV-to-DTV geographic spacing requirements of
§ 73.623(d) with respect to all existing DTV allotments in the
post-transition DTV Table; the principle community coverage requirements of
§ 73.625(a); the Class A TV and digital Class A TV protection requirements in
paragraph (f) of this section; the land mobile protection requirements of
§ 73.623(e); and the FM radio protection requirement of § 73.623(f).
(c) The reference coordinates of a post-transition DTV allotment shall be
the authorized transmitter site, or, where such a transmitter site is not
available for use as a reference point, the coordinates as designated in the
FCC order creating or modifying the post-transition DTV Table of Allotments.
(d) The protected facilities of a post-transition DTV allotment shall be the
facilities (effective radiated power, antenna height and antenna directional
radiation pattern, if any) authorized by a construction permit or license,
or, where such an authorization is not available for establishing reference
facilities, the facilities designated in the FCC order creating or modifying
the post-transition DTV Table of Allotments.
(e) An application will not be accepted if it is predicted to cause
interference to more than an additional 0.5 percent of the population served
by another post-transition DTV station. For this purpose, the population
served by the station receiving additional interference does not include
portions of the population within the noise-limited service contour of that
station that are predicted to receive interference from the post-transition
DTV allotment facilities of the applicant or portions of that population
receiving masking interference from any other station.
(1) For evaluating compliance with the requirements of this paragraph,
interference to populations served is to be predicted based on the 2000
census population data and otherwise according to the procedure set forth in
OET Bulletin No. 69: “Longley-Rice Methodology for Evaluating TV Coverage
and Interference” (February 6, 2004) (incorporated by reference, see
§ 73.8000), including population served within service areas determined in
accordance with § 73.622(e), consideration of whether F(50,10) undesired
signals will exceed the following desired-to-undesired (D/U) signal ratios,
assumed use of a directional receiving antenna, and use of the terrain
dependent Longley-Rice point-to-point propagation model. Applicants may
request the use of a cell size other than the default of 2.0 km per side,
but only requests for cell sizes of 1.0 km per side or 0.5 km per side will
be considered. The threshold levels at which interference is considered to
occur are:
(i) For co-channel stations, the D/U ratio is + 15 dB. This value is only
valid at locations where the signal-to-noise ratio is 28 dB or greater. At
the edge of the noise-limited service area, where the signal-to-noise (S/N)
ratio is 16 dB, this value is + 23 dB. At locations where the S/N ratio is
greater than 16 dB but less than 28 dB, D/U values are computed from the
following formula:
D/U = 15 + 10log10[1.0/(1.0−10−x/10)]
Where x = S/N-15.19 (minimum signal to noise ratio)
(ii) For interference from a lower first-adjacent channel, the D/U ratio is
−28 dB.
(iii) For interference from an upper first-adjacent channel, the D/U ratio
is −26 dB.
(2) Due to the frequency spacing that exists between Channels 4 and 5,
between Channels 6 and 7, and between Channels 13 and 14, the minimum
adjacent channel technical criteria specified in this section shall not be
applicable to these pairs of channels (see § 73.603(a)).
(f) A petition to add a new channel to the post-transition DTV Table or a
post-transition DTV station application that proposes to expand its allotted
or authorized coverage area in any direction will not be accepted if it is
predicted to cause interference to a Class A TV station or to a digital
Class A TV station authorized pursuant to subpart J of this part, within the
protected contour defined in § 73.6010.
(1) Interference is predicted to occur if the ratio in dB of the field
strength of a Class A TV station at its protected contour to the field
strength resulting from the facilities proposed in the DTV application
(calculated using the appropriate F(50,10) chart from Figure 9a, 10a, or 10c
of § 73.699) fails to meet the D/U signal ratios for “DTV-into-analog TV”
specified in § 73.623(c)(2).
(2) Interference is predicted to occur if the ratio in dB of the field
strength of a digital Class A TV station at its protected contour to the
field strength resulting from the facilities proposed in the DTV application
(calculated using the appropriate F(50,10) chart from Figure 9a, 10a, or 10c
of § 73.699) fails to meet the D/U signal ratios specified in paragraph (e)
of this section.
(3) In support of a request for waiver of the interference protection
requirements of this section, an applicant for a post-transition DTV
broadcast station may make full use of terrain shielding and Longley-Rice
terrain dependent propagation methods to demonstrate that the proposed
facility would not be likely to cause interference to Class A TV stations.
Guidance on using the Longley-Rice methodology is provided in OET Bulletin
No. 69, which is available through the Internet at
http://www.fcc.gov/oet/info/documents/bulletins/#69.
Note to § 73.616: When this rule was adopted, the filing freeze announced in
an August 2004 public notice (19 FCC Rcd 14810 (MB 2004)) remained in
effect. For a short period of time after the filing freeze is lifted, until
a date to be announced by a Media Bureau public notice, applicants must
protect Appendix B facilities in addition to any authorized facilities
required to be protected pursuant to this rule section.
[ 73 FR 5682 , Jan. 30, 2008]
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Goto Section: 73.615 | 73.621
Goto Year: 2014 |
2016
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